Apple has released a CPU plugin for PowerMac G4 owners that the company says will provide "more reliable performance." Although Appleis documentation and Web site do not specify this, the update is for dual processor machines only. This installer checks, so installing it on the wrong machine is not possible. According to Apple:

This update of the Apple CPU Plugin is required for Power Mac G4 systems using Mac OS 9.0.4 or later. This update is not needed by and will not be installed on systems using Mac OS X Public Beta.

This software updates the Apple CPU Plugin extension and provides more reliable performance from your Power Mac G4.

What Is InstalledApple CPU Plugin installs the Apple CPU Plugin 2.7 extension in your System Folder.